Patagonian Desert

The Patagonian Desert is a massive, arid region in southern South America.

It is also called the Patagonian Steppe. This desert is the largest in Argentina. It is the eighth-largest desert on Earth. The total area is approximately 673,000 square kilometres.

It sits mainly in Argentina and parts of Chile. To the west, the Andes mountains form a high border. To the east, the Atlantic Ocean meets the land. To the north, the desert turns into the Cuyo Region and the Monte.

Nature uses a specific process to keep this land dry. This process is called a rain shadow. The Andes mountains act as a giant physical barrier. They block moist air from the southern Pacific Ocean. This air cannot reach the inland areas. As a result, the land stays very dry. This is why a desert exists here. Half of the desert is only 200 miles from the ocean. The cold Falkland Current also helps create this aridity.

The desert is a cold winter desert. The average temperature is just 3 degrees Celsius. Temperatures rarely go above 12 degrees Celsius. The region has seven months of winter and five months of summer. Frost is very common throughout the year. However, snow is quite rare because it is so dry. Strong winds blow constantly from the west. These winds are caused by descending cool mountain air. This wind makes the desert a major source of dust for the South Atlantic Ocean.

The climate changes depending on where you stand. The northern coast is much milder. This is due to warm currents from Brazil. In the summer, the northern half is warmer. In the Rio Colorado region, temperatures can reach 31 degrees Celsius. In the south, it is much cooler. Summer temperatures there range from 16 to 24 degrees Celsius. Winter temperatures vary by location. In the south, the mean temperature in Tierra del Fuego is 0 degrees Celsius. The coldest recorded temperature was -33.9 degrees Celsius in Chubut.

The desert has a long and complex history. It began to form during the Middle Miocene. This was between 14 and 12 million years ago. It formed as the Andes mountains rose in the west. Before the mountains rose, the area likely had temperate forests. Volcanoes later covered these forests with ash. Mineral-saturated water seeped into the wood. This process fossilized the trees. Now, these are known as petrified forests.

The landscape features gravel plains, plateaus, and sandstone canyons. Volcanic rocks cover more than 120,000 square kilometres of the desert.

Many animals have adapted to this harsh environment. Some live on the edges where food is easier to find. You can find the guanaco and the puma here. Other animals include the Patagonian gray fox and the mara. Small creatures like the burrowing owl and the tuco-tuco also live here. Even the desert iguana and the Patagonian weasel survive. Plants include desert shrubs like Acantholippia. You can also find tuft grasses like Stipa. Near the Andes, you may see aquatic grasses around seasonal lakes.

Humans have a deep connection to this land. Hunter-gatherers lived here in pre-Hispanic times. The Tehuelche complex is one of the earliest known groups. Later, the Mapuche people influenced the northern steppe. They practiced horse husbandry and controlled trade. In the 19th century, many Europeans migrated here. Welsh immigrants established a settlement at the Chubut River in 1860. The 1870s saw the Conquest of the Desert campaign. This caused a sharp decline in the indigenous population. Today, people raise sheep, goats, and cattle. Some also mine for oil, gas, and coal.

Today, much of the desert is protected. About 12 percent of the ecoregion is in protected areas. This equals 70,970 square kilometres. There are many national parks in the region. These include Los Glaciares and Patagonia National Park. Other areas are wilderness reserves, like El Rincón. These protections help save the unique desert landscape and its wildlife.